Diseases and disorders of the pulmonary system are among the leading causes of acute and chronic illness in the world. Pulmonary diseases or disorders may be organized into various categories, including, for example, breathing rhythm disorders, obstructive diseases, restrictive diseases, infectious diseases, pulmonary vasculature disorders, pleural cavity disorders, and others. Pulmonary dysfunction may involve symptoms such as apnea, dyspnea, changes in blood or respiratory gases, symptomatic respiratory sounds, e.g., coughing, wheezing, respiratory insufficiency, and/or general degradation of pulmonary function, among other symptoms.
Breathing rhythm disorders involve patterns of interrupted and/or disrupted breathing. Sleep apnea syndrome (SAS) and Cheyne-Stokes respiration (CSR) are examples of breathing rhythm disorders. Breathing rhythm disorders may be caused by an obstructed airway and/or by derangement of the signals from the brain controlling respiration. Disordered breathing rhythm during sleep is particularly prevalent and is associated with excessive daytime sleepiness, systemic hypertension, increased risk of stroke, angina, and myocardial infarction. Breathing rhythm disorders can be particularly serious for patients concurrently suffering from cardiovascular deficiencies.
Obstructive pulmonary diseases can be associated with a decrease in the total volume of exhaled airflow caused by a narrowing or blockage of the airways. Examples of obstructive pulmonary diseases include asthma, emphysema and bronchitis. Chronic obstructive pulmonary disease (COPD) refers to chronic lung diseases that result in blocked airflow in the lungs. Chronic obstructive pulmonary disease may develop over many years, typically from exposure to cigarette smoke, pollution, or other irritants. Over time, the elasticity of the lung tissue is lost, the lung's air sacs may collapse, the lungs may become distended, partially clogged with mucus, and/or lose the ability to expand and contract normally. As the disease progresses, breathing becomes labored, and the patient grows progressively weaker. Many people with COPD concurrently have both emphysema and chronic bronchitis.
Restrictive pulmonary diseases involve a decrease in the total volume of air that the lungs are able to hold. Often the decrease in total lung volume is due to a decrease in the elasticity of the lungs themselves, or may be caused by a limitation in the expansion of the chest wall during inhalation. Restrictive pulmonary disease can be caused by scarring from pneumonia, tuberculosis, or sarcoidosis. A decrease in lung volume may be the result of various neurologic and/or muscular diseases affecting the neural signals and/or muscular strength of the chest wall and lungs. Examples of neurologic and/or muscular diseases that may affect lung volume include poliomyelitis and multiple sclerosis. Lung volume deficiencies may also be related to congenital or acquired deformities of the chest.
Pulmonary dysfunctions can also involve disorders of the pleural cavity and/or pulmonary vasculature. Pulmonary vasculature disorders may include pulmonary hypertension, pulmonary edema, and pulmonary embolism. Disorders of the pleural cavity include conditions such as pleural effusion, pneumothorax, and hemothorax, for example.
Pulmonary diseases may be caused by infectious agents such as viral and/or bacterial agents. Examples of infectious pulmonary diseases include pneumonia, tuberculosis, and bronchiectasis. Non-infectious pulmonary diseases include lung cancer and adult respiratory distress syndrome (ARDS), for example.
Early detection and diagnosis of various types of pulmonary diseases and syndromes improves the likelihood of successful treatment. The onset of some types of pulmonary disorders is very gradual. Early diagnosis may depend on the recognition of subtle changes in respiratory conditions that may not be apparent during yearly or even monthly check-ups. The patient may compensate for decreases in respiratory capacity, further obscuring detection and diagnosis. Methods and systems providing earlier and more accurate assessment of pulmonary diseases and disorders are desirable.